Initial revision

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/sandbox/graph/trunk@144575 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/graph/Edge.java

@@ -0,0 +1,128 @@
+package org.apache.commons.graph;
+
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" and
+ *    "Apache BCEL" must not be used to endorse or promote products
+ *    derived from this software without prior written permission. For
+ *    written permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    "Apache BCEL", nor may "Apache" appear in their name, without
+ *    prior written permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+/**
+ * Describes an edge between two vertices of a graph, i.e. a relation between
+ * two arbitrary vertices.
+ *
+ * @version $Id: Edge.java,v 1.1 2001/11/12 16:05:18 jvanzyl Exp $
+ * @author  <A HREF="http://www.inf.fu-berlin.de/~dahm">M. Dahm</A>
+ */
+public class Edge implements Cloneable, Constants, java.io.Serializable {
+  private int        ident;   // unique number, i.e. identifier
+  private static int counter; // produce default numbers
+
+  /**
+   * Create edge.
+   */
+  public Edge() {
+    ident = counter++;
+  }
+
+  /**
+   * @return ident, i.e. identifier of this node
+   */
+  public final int getIdent()  { return ident; }
+
+  /**
+   * @return number of created edges
+   */
+  public static final int getCounter()  { return counter; }
+
+  /**
+   * @return String representation.
+   */ 
+  public String toString() {
+    return toString(PLAIN);
+  }
+ 
+  /**
+   * @param verbose toggle output format
+   * @return String representation.
+   */
+  public String toString(int verbose) {
+    if((verbose == TALKATIVE) || (verbose == V_TALKATIVE))
+      return "Edge(" + ident + ")";
+
+    return "";
+  }
+
+  /**
+   * Access for visitor patterns
+   */
+  public void accept(Visitor v) { v.discoverEdge(this); }
+
+  /**
+   * @return deep copy
+   */
+  public Edge copy() {
+    try {
+      return (Edge)clone();
+    } catch(CloneNotSupportedException e) {}
+
+    return null;
+  }
+
+  /** Check for equality.
+   */
+  public boolean equals(Object o) {
+    if(!(o instanceof Edge))
+      return false;
+
+    Edge e = (Edge)o;
+    return e.ident == ident;
+  }
+}